RecordId • tldraw Docs

A branded string type that represents a unique identifier for a record. The brand ensures type safety by preventing mixing of IDs between different record types.

type RecordId<R extends UnknownRecord> = string & {
  __type__: R;
};

Example

// Define a Book record
interface Book extends BaseRecord<"book", RecordId<Book>> {
  title: string;
  author: string;
}

const bookId: RecordId<Book> = "book:abc123" as RecordId<Book>;
const authorId: RecordId<Author> = "author:xyz789" as RecordId<Author>;

// TypeScript prevents mixing different record ID types
// bookId = authorId // Type error!